<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>事件流</title>
    <style>
        .container
        {
            width: 400px;
            height: 400px;
            background-color: red;
            display: flex;
            align-items: center;
            justify-content: center;
            
        }

        .item
        {
            width: 200px;
            height: 200px;
            background-color: blue;
        }
    </style>
</head>
<body>

    <div class="container">
        <div class="item">
        </div>
    </div>

    <script>
        var containerEl = document.querySelector(".container");
        var itemEl = document.querySelector(".item");
        
        containerEl.addEventListener("click",function(){
           console.log("我是container");
        });

        itemEl.addEventListener("click",function(){
           console.log("我是item");
           console.log(event);
        });
    </script>
    
</body>
</html>